Page:Small-boat sailing; an explanation of the management of small yachts, half-decked and open sailing-boats of various rigs; sailing on sea and on river; cruising, etc (IA smallboatsailing01knig).pdf/35

 stern without fuss, instead of forming a following wave to act as a drag on her speed, as is the case if the stern be finished off too abruptly.

LATERAL RESISTANCE—LEEWAY

But when a boat is sailing with the wind on her side, the effect of the wind is not only to drive her forwards, but sideways as well, and she makes what is called leeway. A boat of very shallow draft will, when close-hauled, drift bodily to leeward, and make no headway at all. This tendency to make leeway has to be checked as much as possible by increasing the lateral resistance of the water; and this done by giving the boat a deep keel or a centre-board, or by otherwise providing an extensive area of lateral surface below the water-line.

The lateral resistance opposed by the water to a ship's side acts through a point which is, roughly speaking, the centre of the immersed portion of the vessel's side, and this point is termed the Centre of Lateral Resistance. Thus, in Fig. 1, a is the centre of lateral resistance. A rope made fast to the vessel's side at this point would tow her broadside on; but were it made fast before or aft of that point, the resistance would be greater on one side than on the other, and the rope would pull either the stern or the bow round, as the case might be.